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Protocol for Determining Ultraviolet Light Emitting Diode (UV-LED) Fluence for Microbial Inactivation Studies
Ataollah Kheyrandish1, Madjid Mohseni1, Fariborz Taghipour1
1Department of Chemical and Biological Engineering , The University of British Columbia , 2360 East Mall , Vancouver , BC V6T 1Z3 , Canada.
Environmental Science & Technology
|June 2, 2018
Summary
A new method accurately measures UV-LED fluence in water, crucial for designing effective UV disinfection reactors and understanding microbial inactivation kinetics. This addresses limitations of older UV lamp methods.
Area of Science:
- Microbiology
- Photochemistry
- Environmental Engineering
Background:
- Accurate fluence determination is vital for microbial inactivation kinetics and UV disinfection reactor design.
- Ultraviolet light emitting diodes (UV-LEDs) offer advantages over traditional mercury lamps but lack standardized fluence measurement methods.
- Existing methods for UV mercury lamps are unsuitable for UV-LEDs due to their unique characteristics (low power, polychromatic output, specific radiation profiles).
Purpose of the Study:
- To develop and validate a novel method for determining average fluence in a UV-LED water disinfection experimental setup.
- To adapt and refine existing fluence measurement parameters for UV-LED applications.
- To investigate the impact of UV-LED polychromatic output and radiation profiles on fluence measurements.
Main Methods:
- Developed a method to estimate average fluence by measuring irradiance at multiple points under collimated, uniform radiation on a Petri dish.
- Defined new correction parameters and revised existing ones to quantify radiation collimation and uniformity.
- Selected two UV-LEDs (262 nm and 275 nm) with distinct radiation profiles to represent typical UV-LEDs for microbial inactivation studies.
Main Results:
- Successfully established a method for average fluence determination in UV-LED water suspension setups.
- Quantified radiation collimation and uniformity using revised and new correction parameters.
- Identified the influence of polychromatic output and radiation profiles on fluence measurements.
Conclusions:
- The developed method provides a reliable way to determine UV-LED fluence in water, essential for accurate microbial inactivation studies.
- The study offers revised parameters and new correction factors for precise fluence quantification with UV-LEDs.
- The findings aid in optimizing UV-LED reactor design and setup configurations for effective water disinfection.
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